Police in Larimer County, Colo.—as well as the national media—spent Thursday afternoon tracking a homemade helium balloon thought to contain a 6-year-old boy, Falcon Heene. When the balloon landed after more than two hours in flight, however, it was empty—it turns out Falcon was hiding in a box in his family's garage. This incident raises all sorts of questions about balloon travel, answered below.
Is it legal to pilot a homemade balloon? Sure. Anyone can construct and fly a homemade engineless aircraft that's less than 155 pounds without permission from the Federal Aviation Administration. You don't even need a pilot's license. The balloon that sailed across Colorado appeared to be extremely lightweight and would probably qualify. If the aircraft is more than 155 pounds, you need a license to pilot the balloon and FAA certification. First, an FAA inspector comes to look at the aircraft. If it looks airworthy, you can begin test flights, with certain restrictions—you have to stay within a limited geographical area, for example, and can't fly at night. If that goes well and the inspector approves your flight log, you can fly your experimental aircraft anywhere in the United States.
How much helium do you need? A standard gas balloon—as opposed to a hot-air balloon—requires about 1,000 cubic meters, or 35,000 cubic feet, of helium. (Here's what they look like.) That's about 120 of the tall helium bottles you might find at the party store. To fly a smaller craft, like the experimental balloon that soared around Colorado, you'd need a lot less. A single tank of helium typically lifts about 14.4 pounds. So to lift a 50-pound 6-year-old you'd need about 4 tanks.
Do a lot of people fly helium balloons recreationally? No—they're too expensive. Each tank of helium costs anywhere from $75 to $150, depending on whether you buy in bulk. A single flight in a helium balloon, then, will often cost about $10,000. Pilots typically fly gas balloons only once a year at the annual Albuquerque International Balloon Fiesta.
Hot-air balloons are cheaper and more common. The balloon itself costs between $25,000 and $50,000, on average, and the cost of a single ride is merely the price of the propane used to heat the air, or about $50. It's also easier to get a license for a hot-air balloon than a gas balloon, in part because they can't go very far. Hot-air balloons stay aloft for about an hour and might travel a few miles. Gas balloons can fly for three days at a time and traverse the entire continent.
Do you need permission to launch a balloon out of your backyard? Depends where you live. In rural areas that aren't close to any airports, you don't need permission to launch a balloon, as long as you stay below 18,000 feet. (Falcon Heene's balloon reached just 7,000 feet.) It gets more complicated the closer you get to cities and airports. Near smaller airports, you don't need explicit FAA permission, but you do need to be in radio contact with the air traffic controller. Near large airports like LAX or LaGuardia, you need advance permission to enter their airspace. Same if you want to fly higher than 18,000 feet. In both of these cases, you also need to bring a transponder on board so air traffic controllers can follow you on radar. Some airspace is off-limits altogether, like the sky above military bases or Washington, D.C.
How do you steer a balloon, anyway? Balloons fly in the direction of the wind. In order to choose your direction, therefore, you have to fly at an altitude where the wind is blowing the way you want to go. Changing direction is a lot easier in a hot-air balloon than in a gas balloon, since it's simpler to go up and down. To ascend in a hot air balloon, the pilot just fires up the burner, which heats up the air inside the balloon, which lifts it. To descend, she reduces the frequency of the heat bursts, or lets the air out of a flap at the top of the balloon. A gas balloon is different. To climb, the pilot throws out ballast—like sand or water. To descend, she either lets out a little helium (making sure not to pull the rope connected to the "ripout port," which dumps all the helium at once) or waits for nightfall, when the gas cools and the balloon sinks without interference.
How do you know which way the wind is going at different altitudes? You can call FAA Flight Services, which will brief you on different wind directions and speeds at different altitudes in your area (1-800-WXBRIEF). Or you can send up your own weather balloon. Just buy a "pilot balloon" and release it before your flight. Using a compass and timer, you can see which direction it's drifting at what altitude. (For a handy altitude calculator, click here.) During long flights in gas balloons, the pilot will often carry a satellite phone in order to receive updates from a meteorologist.
Do balloons often lose control and need rescuing? Not really. First off, you can't exactly "lose control" when you don't have it in the first place. Secondly, once you're in the air, you're in charge—there's not a lot the police or the military can do to save you if something goes wrong.
Newscasts keep referring to the balloon as "UFO-shaped." How did the flying saucer become the universal shape for aliens? It traces back to a well-publicized UFO sighting by a pilot named Kenneth Arnold in 1947. While flying across Washington state, he claimed to have spotted nine shiny objects flying in a diagonal formation. He described their shapes as "saucer"- or "disc"-like. The incident led to hundreds of copycat sightings across the country. Since then, the term flying saucer has been synonymous with UFOs. Other reported UFO shapes include triangles, cylinders, and tear drops.
Got a question about today's news? Ask the Explainer.
Explainer thanks Jonathan Trappe of ClusterBalloon.com.
AP video: Balloon aircraft over Colorado